Inductive sensors are known. An inductive sensor is described in German Unexamined Patent Application DE 42 28 888 A1, for example. Conventional inductive sensors are used for detecting rotational speeds, for example. An inductive sensor cooperates with a magnet. A voltage is induced in a coil due to change in the magnetic field caused by a magnet moving past. A rotational speed signal, for example, may be picked up in this manner.
Another option is to provide a magnet in the sensor itself, the magnet cooperating with ferromagnetic components. A ferromagnetic object may thus likewise be detected via a change in the magnetic field.
Inductive sensors are also known from practice which react to metals of any type, and generate a signal when a metallic body is in the vicinity of the sensor.
One disadvantage, among others, of such known inductive sensors is that a switching signal is generated in the mere presence of a metallic component. Therefore, such sensors have only limited suitability for detecting dynamic processes. In addition, known inductive sensors are relatively sensitive to interferences. Thus, for example, metal dust or shavings, etc. adhering to the sensor may result in an erroneous detection.